The head of the United Nation's Food and Agricultural Organisation (FAO) says two-thirds of the world's population could be threatened by water shortages by 2025.
Jacques Diouf, director-general of the FAO, said in a speech in Rome on World Water Day that 1.2 billion people currently live in areas with insufficient water.
He says an additional 500 million could soon face shortages.
"The international community has the means to greatly improve the management of our water resources and to allow more people access to water," Mr Diouf said, addressing an FAO conference on the issue.
Climate change and the pollution of a large number of rivers used for irrigation are making it increasingly difficult for southern countries to provide themselves with food, he said.
Ugandan Environment Minister Maria Mutagamba said at the conference that Africa has 9 per cent of the planet's water resources, but uses only 3.8 per cent.
Water resources on the continent are not well-distributed geographically, she said.
Ms Mutagamba also noted that the level of Lake Victoria, Africa's largest freshwater reserve, fell two metres below normal in 2005.
"Because of common measures taken by countries with water access, we were able to increase the level by 70 centimetres (28 inches) in 2006, but we are worried about next season," she said.
The European commissioner for development, Louis Michel, sent a message to the conference detailing Europe's efforts on water access.
Since 2002, Europe has committed $US535 million for short-term water-access projects, as well as $US475 million for long-term projects, he said.
Italy's deputy foreign minister Patrizia Sentinelli said access to water should be viewed as a basic and legal human right and not be subject to private interests seeking to profit from it.AFP
